More Kobalt compressor problems

I have a 17 gal Kobalt compressor that I've barely used but is beyond the 30 day grace period, its problem is when it begins to fill it cuts out or trips the breaker. When I used it before it didnt do this, it worked fine if only in limited use. What's going on here, is there something obvious that I'm missing(as usual) or is the regulator knob worn out as another fella had happen. Not much help from the trouble guide. Thanks Means